DETERMINATION OF THE CONCENTRATIONS OF THE STEROIDS ESTRADIOL, PROGESTERONE AND TESTOSTERONE IN BOVINE SERA - COMPARISON OF COMMERCIAL DISSOCIATION ENHANCED LANTHANIDE FLUORESCENCE IMMUNOASSAY KITS WITH CONVENTIONAL RADIO AND ENZYME IMMUNOASSAYS

The performance of three conventional enzyme and radioimmunoassays rou tinely used to detect residues of anabolic steroids in cattle sera wer e compared with dissociation enhanced lanthanide fluorescence immunoas say (DELFIA) kits designed for the hospital market. Slight modificatio ns to the kit reagents were required for the analysis of bovine sera. Owing to the large sample volumes used in conventional assays, detecti on limits were generally better than those obtained with DELFIA kits, however, assay reproducibility was enhanced using the DELFIA technolog y. Comparison of sera obtained from cattle implanted with anabolic ste roids revealed a good correlation between alternate methods (r(2) from 0.91 to 0.97). The DELFIA kits offer a faster method for measuring es tradiol, progesterone and testosterone with adequate sensitivity and i n a safer environment than that encountered using radioimmunoassays.